Japanese Patent Application Publication No. 2006-320150 (JP2006-320150A) discloses a linear actuator (an electrical machine apparatus) including a stator and a mover that reciprocates with respect to the stator to generate vibration. The mover includes a pair of permanent magnet arrays each including a plurality of permanent magnets arranged in an array in a motion direction in which the mover reciprocates. The stator includes an armature including a stator core and an excitation winding. The stator core includes first and second magnetic pole portions facing magnetic pole surfaces of the plurality of permanent magnets, and a yoke portion coupled to the first and second magnetic pole portions via a coupling portion. The yoke portion is disposed outside the excitation winding in the radial direction of the mover.